A new and novel apparatus, the High Aspect Rotating-Wall Vessel (HARV), developed by NASA at the Johnson Space Center, Houston, TX, produces three dimensional cellular aggregates (spheroids) under low fluid shear conditions, an aspect of simulated microgravity. The vessel rotates cells and culture medium in a disk-shaped chamber about a horizontal axis with zero headspace. Adequate gas exchange is maintained across a membrane lining one face of the chamber. Under a collaboration with NASA, CytoDiagnostics, Inc. (CDI) has studied the growth of human glioma and prostate cell lines as three dimensional spheroids in the HARV apparatus. Using molecular biomarkers, CDI and its collaborators found DNA content, actin organization, and expression of unique tumor biomarkers correlated to in vivo prostate cancer molecular changes, but not monolayer cultures from stationary grown tissue culture flasks. This proposal is designed to confirm and extend our observations in this prostate tumor model using proprietary tumor markers, oncogenes, tumor suppressor genes, and androgen receptor probes to assess the comparisons of the in vitro growth of spheroids versus monolayers and prostate core biopsies processed by our laboratory. The cell lines to be employed include PC3-PF, PC3-MF, and LNCaP prostate cell lines which will be grown as monolayers and three dimensional spheroids using the HARV technology and studied temporally for differential, quantitation of in situ expressed biomarkers using a CAS-200 image analysis system. Once an optimized intermediate biomarker profile with high fidelity to the in vivo tumor is established, the model will be used to assess selected chemotherapeutic agents [suramin, taxol, finasteride] to assess the utility of the model for evaluation of their therapeutic potential. The 3D spheroid technology being developed will provide a useful in vitro model to assess new treatments and study mechanisms of action for prostate cancer.